A method for determination of pore volume characteristics and matrix thermal conductivity using sample thermal conductivity measurements saturated in series with three fluids with different thermal conductivity is known (Popov et al. Interrelations between thermal conductivity and other physical properties of rocks: experimental data. Pure Appl. Geophys., 160, 2003, p.p. 1137-1161). The method is based on the determination of a porous material sample porosity, matrix thermal conductivity and shape of the pores and cracks simulated using rotation ellipsoid and characterized by the same aspect ratio. The porous material sample porosity, matrix thermal conductivity and aspect ratio of the ellipsoids simulating pores and cracks are determined by solving a set of three nonlinear equations in three unknowns using thermal conductivity measurements on a porous material sample saturated in series with three fluids of a known different thermal conductivity. The equations in this set are equality values of theoretical and experimental thermal conductivity of the samples of a pore-fractured material saturated in series with three fluids of a known different thermal conductivity. The theoretical thermal conductivity values are determined using the known method of effective-medium theory autocorrelation which enables expressing a porous material thermal conductivity value depending on the thermal conductivity of the matrix, fluid filling the pores and cracks, porosity and the ellipsoids' aspect ratio. The porosity of the porous material sample, matrix thermal conductivity and aspect ratio of the ellipsoids simulating the pores and cracks are determined for the entire sample in total without considering these values' variations within the sample.
It is also known a method for determination of pore volume characteristics and matrix thermal conductivity (Popov et al. Physical properties of rocks from the upper part of the Yaxcopoil-1 drill hole, Chicxulub crater. Meteoritics & Planetary Science 39, Nr 6, 2004, p.p. 799-812), consisting in the successive saturation of a porous material sample with at least two fluids with the known different thermal conductivity and determination of the sample porosity. After each saturation of the porous material sample with the fluid the sample thermal conductivity is measured. Based on the cumulative results of thermal conductivity measurement on the porous material sample pore volume characteristics and porous material sample matrix thermal conductivity are determined by the known ratio. The known method provides for determination of the pore-fractured space and matrix thermal conductivity for the sample in general, which, in case of non-uniform samples results in the loss of critical information on the variability of the sample properties within the sample and does not provide the record of the porosity distribution which, given the sample non-uniformity, also results in the loss of important information on the sample properties.
The suggested method provides for the record of the pore volume characteristics' distribution within a sample, location of the sample zones with maximum and minimum pore volume characteristics' and matrix thermal conductivity values, determination of the sample porosity in certain zones of the sample. This detailed distribution of these characteristics enables locating weakened zones, non-uniformity zones in the sample. This, in its turn, enables judging, for example, of the most probable destruction zones within the porous material.